Pleased is an emotion. Only living things can experience emotions so only living things can be pleased. Pleasant is a characteristic. It causes the emotion 'pleased'. Anything at all can be pleasant. We had a pleasant conversation. The conversation was pleasant. I was pleased to speak with her. Pleased was the emotion I felt. I was pleased because the conversation was pleasant.

Pleased in contemporary English means happy, contented or satisfied about something, examples are: [I am pleased to meet you] or [We are pleased to announce that the project was successful]. Pleasant can mean agreeable. It carries the feelings of the speaker examples are: [The new tech on the wrist watch is a pleasant surprise] or [Have a pleasant year, day or week ahead]

Pleased usually means 'satisfied' - you like what has happened : 'I was pleased with my result in the exam.' It can also be used as a courtesy to someone : 'Pleased to meet you' ; 'Pleased to have met you.' Pleasant means 'agreeable', 'satisfying' - it describes the feeling you have when you are pleased by something : 'We had a pleasant evening' ; 'There was a pleasant breeze' NB. Although the two words have a common stem, their pronunciation is different : 'ea' in pleased is 'long' as in eat, seat, heat, meet, feet ; 'ea' in pleasant is 'short' as in egg, head, dead, bed, red, get.

'Pleasant' can describe many things, both animate and inanimate. You can say a pleasant . . . . view, meal, day, trip, dream, person . . . really almost anything. Synonymns might be: good, beautiful, enjoyable, etc. 'Pleased' can only describe animate things--usually people--because it is an emotion. It means something like 'happy with the way things turned out. Synonymns: satisfied, proud, content. So, you can have a pleasant trip, but a pleased trip is impossible, because the trip can't feel pleasure.

Since your question has already been well answered, no more need be said. I will only bore you with a little bit of grammar. Both words are adjectives, however there is an important difference: "pleased" is the past participle of a verb ("to please") but "pleasant" is not a participle. So "pleasant" is just an ordinary adjective, but "pleased" is a very special kind of adjective. Participles can do special things that ordinary adjectives are not able to do. And what are those things? Although participles are not verbs, they can do HALF of what verbs can do. To demonstrate what I mean, I will use a different verb, "sing". I don't want to use "please" because its past tense and its past participle are the same, and this will confuse you. With "sing", the past tense is "sang" but the past participle is "sung". This will make the example more clear. A verb can have both a subject and an object: "The girl sang a song". (subject = girl, object = song) A past participle (which is NOT a verb) behaves like a verb with the important exception that it never has a subject: "The girl sang a song very well". (no participle) "A song was sung very well". (past participle) Notice that the sentences are the same except that the past participle can't have a subject so you don't know who sang the song unless you add something extra to the sentence like "by the girl". For this reason, participles are said to create "passive" sentences, meaning that they express action without letting you know what made the action happen. Another: "Sung in the key of B-minor, Bach's Mass is one of the greatest choral works he created." Note how the opening phrase acts as an adjective to describe "Bach's Mass". Note how "sung" feels like a verb having NO SUBJECT, it is not.